Therapist: “People suffering from Post Traumatic Stress Disorder, or PTSD, often struggle with social anxiety. PTSD symptoms are especially severe for people who already struggled with anxiety prior to developing PTSD. PTSD is common in military veterans, so it is important for the military to test people for anxiety disorders before they join in order to prevent people who will be more heavily impacted by PTSD from suffering its consequences.”
Which one of the following principles, if valid, most helps justify the conclusion of the argument?